Automatic take-up for brakes



March 13, 1934. v F. H. BARTZ AUTOMATIC TAKE-UP FOR mums Filed March 3.1930 3&7 invemtizm ta mpwvemamts in autu always keep its teeth in linewith am teeth of the matic taize up for 55m, it more esgzejaws 21 andthe teeth @i. the Jaws 37, when the ciaily consists mi i'ifliifiafi011:- in mm mm are in Working Talisman. annexed {am-Ems. Any desiredform m easing 8 mw 125: used m The pm: 2 m my invent-5mm is is pzavldeEmma the mechanism. have a removable; autsmatic take-up t0 Km time @f mmm and a 2mm cows" asks "1. At the 30% any w 21 are smojest friction,such mm end emf the casims; 1% 3a pssitioned. brake wc etcuizh b Rim Gmthis sham the 08, 15,155 and l? seamed normal EQELEZJEQ'EZE 0f the pew;within the casing, and wme'rs" a, M9311: 1. 3 via wear 0011"" 1,utsi-mum f5 is attmahed. To this is aismchefi, A 1M 12 whim the wear; aisms W32 19m w a font menial 13 123m m is mplznssfl. A 14 serves w 52araised. I .m, View, stsm Q where i WW fanned in the z sawing sue mmw,@Li may wand m 5531 mp ser l8 adapmioz A Q '1 lmfi eflymg and will b2round m z feexures 0i inventim: an its @1315 wheneve? &

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me Mamie-Li: fiz eem Wimnevew 3 5 m m a. lawaa img actiqm m a 1mm 'm Jmama ends of a 322 the imam v .fimvs am waved chmm m the m in @magemmtmm auwmdmle mt 9, mam m mil y as m fi my @mcezzl, @mm 1 is seam; a At Yazzle i of QM au'wmcbile. Ki; 32 2: 5;, M3 9 51mm by a 1mm fl a As msgage the "me ems 02 the ba2, cwmm mm and any is Rag M bass, a short m mm awaken, m the (Fig. 3) m mint (Em 3), tiihfim stem. Tnis crankengagestme flaw-saw mm? m bmke is applies? cam 51m 23 and encl 8 0f; thewarming stem E which mww w m m 9 as as mm. fiaauzmhar mm mm mm 10 block29 is lifted by the cam 1'7. As a result of this the take-up jaws 27move down one tooth relative to the stem 9. When the brakes are releasedthe block 29 follows the surface of cam 17, thus dropping down adistancecorresponding to the normal brake-shoe clearance, but the jaws 21 byfollowing the cams 16 drop through a greater distance, and as a result,the take-up jaws 21 move down relative to the stem 9 to the extent ofone tooth and the stem 9 and this stem has thus been raised to theextent of one tooth relative to both jaws 21 and 27. These movementscomplete the adjustment. In any subsequent application of the brakes,jaws 21 and 27 and the stem 9 move together as a unit until suflicientwear of the brake bands again develops to permit the stem 9 being movedupward relative to said jaws in the manner described above.

The operation of my device will be readily understood, if for the sakeof illustration it is assumed that the stem 9 were only actuated by asingle cam, such as the cam 1'7. On this assumption if the cam wererocked from its lower to its higher position the stem 9 would be raised,the crank 7 moved and the stem 6 would set the brake band 3 inside therim 2 (Figs. 1 and 2). An opposite movement of the cam would lower thestem 9, the crank '7 and release the brake.

Inorder to insure that the stem 9 will always move downward to pressagainst the teeth of the jaws, a compression spring 19, shown in Fig. 3,engages the end of crank 7. The stem 6 actuated by the crank 7 moves theends of the brake band away from each other to set the brake. and aspring, not shown, tends to pull the ends of the band toward each otherto release the brake, when the crank is moved in the opposite direction.The only occasion when a manual adjustment of the stem 9 is required iswhen new brake shoes are being installed. Under these conditions theinitial slack may be larger than can be taken up by a single operationof the differential cam 16, 1'1. In this event itwould be necessary tolift the stem 9 and the crank 'l a short distance 37 (Fig. 3) in orderto initially bring the brake shoe clearance within the normal range ofthe mechanism.

What I claim is:

1. In self compensating devices, a drum, means for frictionally engagingthe drum, a foot lever for actuating the latter, and compensating meanscomprising differential cams attached to a single and the retardingmeans, said cams being adapted to differentially act on the stem.

3. In brake mechanisms, a wheeled vehicle, L

a brake drum attached to one or more wheels of the vehicle, cooperatingbrake shoes susceptible to wear, a foot lever for operating the brakeshoes through a single shaft, a cam on the shaft for taking up the wear,and another cam actuating means on the same shaft, both camsconstituting a unit for applying the brake shoes.

4. In brake mechanism, a drum, brake shoes for engaging the drum, abrake lever for operating the shoes, differentially actuating cams on asingle shaft, one of said cams serving to automatically take up the wearof the brake shoes and the other cam adapted to apply the brake shoes tothe drum, and a foot lever for operating the single shaft.

FRED H. BARTZ.

